【iCore4 双核心板_ARM】例程五：SYSTICK定时器 实验——定时点亮LED

实验原理：

　　通过STM32的三个GPIO口驱动三色LED的三个通道，设定GPIO为推挽输出模式，采

用灌电流方式与LED连接，输出高电平LED灭，输出低电平LED亮，通过系统定时器实现

1s定时，每秒变换一次LED颜色。

核心代码：

int main(void)
{

/* USER CODE BEGIN 1 */
static int led_work_status;

/* USER CODE END 1 */

/* MCU Configuration----------------------------------------------------------*/

/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

/* USER CODE BEGIN Init */

/* USER CODE END Init */

/* Configure the system clock */
  SystemClock_Config();

/* USER CODE BEGIN SysInit */

/* USER CODE END SysInit */

/* Initialize all configured peripherals */
  MX_GPIO_Init();

/* USER CODE BEGIN 2 */

/* USER CODE END 2 */

/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
  {
/* USER CODE END WHILE */

/* USER CODE BEGIN 3 */
if(systick.second_flag == 1){
            systick.second_flag = 0;
            led_work_status += 1;
if(led_work_status > 2)led_work_status = 0;
switch (led_work_status){
case 0 :
                    LED_RED_ON;
                    LED_GREEN_OFF;
                    LED_BLUE_OFF;
break;

case 1 :
                    LED_RED_OFF;
                    LED_GREEN_ON;
                    LED_BLUE_OFF;
break;

case 2:
                    LED_RED_OFF;
                    LED_GREEN_OFF;
                    LED_BLUE_ON;
break;

default:

break;    
            }            
        }
  }
/* USER CODE END 3 */

}

void HAL_SYSTICK_Callback(void)
{
//中断时间1ms，每ims进入一次中断
static int counter = 0;

if((counter ++ % 1000) == 0){
        systick.second_flag = 1;    
    }
}

源代码下载链接：

链接：http://pan.baidu.com/s/1eSclNOI 密码：cddu

iCore4链接：